The Effect Of CCDC8 Gene Silencing On The Growth Of Transplanted Breast Cancer In Nude Mice

ObjectiveIn recent years,there is a trend of younger breast cancer, and the triple negative breast cancer has a poor prognosis. Triple negative breast cancer is considered to be the result of multi-stage, multi-factor and multi-gene interaction. In this study, we selected the triple negative breast cancer cell line MDA-MB-231.By lentiviral vector method silencing the CCDC8 gene of this cell line and constructing the model of nude mice transplanted with breast cancer, we can observe the effect of gene silencing on the proliferation ability of breast cancer MDA-MB-231 cells and the growth of breast cancer xenografts in nude mice.Methods1. Two siRNA interference fragments were synthesized by using KD1?KD2 sequence and stably transfected into MDA-MB-231 cells by lentiviral vector method.2. The lentivirus stably transfected cells with high knockout rate of CCDC8 gene were screened by qRT-PCR.3. The cell cloning ability of MDA-MB-231 cells with lentivirus stably transfected was observed by cell clone formation assay.4. Flow cytometry was used to observe the changes of cell cycle and apoptosis rate of MDA-MB-231 cells with lentivirus stably transfected.5. MTT assay was used to detect the proliferation ability of MDA-MB-231 cells with lentivirus stably transfected.6. Establish the animal model of nude mice with breast cancer transplanted and observe the changes of tumor volume and weight.Results1. qRT-PCR showed that KD2-siRNA could effectively inhibit the expression of CCDC8 gene (P <0.01).2. The result of cell clone formation assay showed that the cell cloning ability of MDA-MB-231 cells after CCDC8 gene silencing was decreased (P <0.01).3. The results of flow cytometry showed that the MDA-MB-231 cell cycle was blocked in G1 phase (P<0.01) and the apoptosis rate was increased after CCDC8 gene silencing (P <0.01).4. MTT assay showed that the proliferation ability of MDA-MB-231 cells was inhibited after CCDC8 gene silencing (P <0.01).5. The growth rate of nude mouse breast cancer xenografts was reduced after subcutaneous injection of MDA-MB-231 cells with CCDC8 gene silencing (P<0.01).Conclusions1. The cell proliferation ability of triple negative breast cancer cell line MDA-MB-231 after CCDC8 gene silencing was decreased and the apoptosis rate was increased.2. CCDC8 gene silencing can inhibit the growth of breast cancer xenografts in nude mice.